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Bottom-up fabrication of nano carbon-inorganic hybrid materials for photocatalytic hydrogen production

Final Report Summary - CARINHYPH (Bottom-up fabrication of nano carbon-inorganic hybrid materials for photocatalytic hydrogen production)

Executive Summary:
CARINHYPH dealt with the bottom-up assembly route of nanocarbon-based hybrids, their structural and opto-electronic characterisation, with the view of producing more efficient photocatalysts. It has carried out activities in four main areas: fabrication of materials, multiscale characterisation and optoelectronic studies, photocatalytic testing and charge transfer measurements, and exploration of semi-industrial implementation.

The synthesis of hybrids included the controlled production of nanobuilding blocks, their chemical conditioning through different chemical functionalisation routes and controlled assembly into complex hybrid architectures. Altogether, the parameter space explored includes the exploration of the following variables: nanocarbon type and volume fraction (MWNT, SWNT, graphene), chemical functionalisation (e.g oxidation by acid treatment, diazo-coupling, microwave-assisted, use of linking agents), metal oxide (Nb2O5, TiO2, Ta2O5, ZnO, SnO and NiO), and hybrid architecture (inorganic-coated nanocarbon membranes, 3D gyroid inorganic architectures, electrospun fibres, cellulose scaffold-based and CNT fibre-based). This has resulted in a library of over 60 different hybrids produced in the project.

A wide range of characterisation techniques has been used to analyse the complex structure of these hybrids. Of particular importance as been the use UPS and Raman spectroscopy, which confirm the formation of an electronic heterojunction between the nanocarbon and the semiconducting metal oxide. For selected hybrids, we have developed techniques to study the electronic structure of the junction and transport properties across it.

Photocatalytic tests on hybrids have shown record-high H2 production values under UV irradiation of mesoporous Ta2O5 gyroids with and without Pt co-catalyst. Nanocarbons are seen to improvement photocatalytic activity when added in small volume fractions. Through a rigorous study of charge transfer between MWNTs and TiO2 by pump-probe measurements and test-model photocatalytic reactions we provide insights into interfacial charge transfer mechanisms and photocarrier lifetimes.

The perspectives for industrial implementation of the materials and processes developed in CARINHYPH have also addressed. Selected hybrid catalyst were tested under semi-industrial conditions and compared with commercial materials. This enabled a first projection for scale up including performance, production and cost. The roadmap analysis proposed includes potential EHS impacts of these novel materials and eventual factors (i.e. psychochemical properties) affecting their toxicity, as well as a life cycle analysis contrasted against established technologies for hydrogen production.

Project Context and Objectives:
CARINHYPH project deals with the hierarchical assembly of functional nanomaterials into novel nanocarbon-inorganic hybrid structures for energy generation by photocatalyic hydrogen production, with Carbon NanoTubes (CNTs) and graphene the choice of nanocarbons. The scientific activities include the development of new functionalisation strategies targeted at improving charge transfer in hybrids and therefore their photocatalytic activity, and in transferring these synergistic effects by assembling the hybrid units into macroscopic structures. Different types of hybrid architectures are explored: Hybrid 1 – consisting of nanocarbon membranes coated with the inorganic compound by atomic layer deposition; Hybrids 2 – consisting of inorganic gyroids impregnated with the nanocarbon; Hybrid 3 - electrospun hybrid fibres; Hybrid 4 – cellulose-based hybrids; and Hybrid 5 – based on continuous macroscopic fibres of CNTs. We specifically aim to tailor interfacial charge and energy transfer processes by means of chemical functionalisation and evaluate them with photochemical and transient spectroscopy, as well as explore the effect of the nanocarbon as a substrate and heat sink, which stabilises smaller semiconductor particles and reduces agglomeration that will result in larger accessible surface areas. Two industrial partners in the consortium, a nanocarbon supplier and a potential end user, guarantee that both ends of the production line are taken into account for the development of new technologies and the production of a roadmap for industrial deployment. This roadmap will also measure sustainability of processes and materials developed in this project in terms of environmental and economic impact as compared to state-of-the-art techniques for the production of hydrogen by the use of adequate Life Cycle Costing (LCC) and Life Cycle Assessment (LCA) approaches. Interaction with and Industrial Advisory Board (IAB) increases the potential development in other application areas of the call besides hydrogen production (electronics, sensors, energy storage and biomedical devices).

The overall aim is to develop different architectures of nanocarbon/semiconducting metal oxide heterojunctions, determine their optoelectronic properties and charge/energy transfer mechanisms and establish their potential as photocatalysts, particularly for hydrogen production. The project has a Work Package (WP) organisation based on the stages to produce these new hybrids, followed by the study of their multi-scale structure and properties, and including a lifecycle analysis and roadmap for industrial deployment; thus, covering the whole cycle from synthesis of nanobuilding blocks to exploitation and disposal of materials. More specifically, the objectives are: to ensure reliable provision of high quality carbon nanotubes and graphene to the project partners, as well as the corresponding characterisation data (WP1); develop innovative functionalisation protocols to improve the dispersion and processability of high purity nanocarbons; the preparation of the nanocarbon surface to create nancarbon assemblies and to enhance the decoration with inorganic coatings from either molecular precursors or thin amorphous, polycrystalline or single-crystalline film deposition for nano-hybrid fabrication (WP2); manufacture and assembly of organic-inorganic building blocks and their assembly into 3D networks (WP3); in-depth characterisation of the hybrids in terms of the structural features that can affect their photocatalytic performance (WP4); evaluate the overall photocatalytic performance of the nanocarbon-inorganic hybrid materials for the degradation of organic compounds and the splitting of water into hydrogen and oxygen (WP5); investigate light harvesting/charge transfer at and across multifunctional/advanced interfaces composed of inorganic semiconductors and nanocarbons (WP6); development of a novel photoreactor concept for solar photochemical hydrogen production with integrated nanocarbon-inorganic hybrid materials (WP7); and comparison of the processes and materials developed in this project with today’s means for the production of hydrogen in order to illustrate their risks and benefits for the environment, to assess their sustainability throughout their whole life cycle from manufacturing to disposal (WP8).

Project Results:
The project has succeeded in producing an enormous library of nanocarbon/metal oxide hybrids with different architectures, studied their structural, interfacial and optoelectronic properties and established their performance as photocatalysts, particularly for H2 production under UV irradiation. A thorough LCA has been carried out for selected hybrid catalysts, covering from the synthesis of raw materials up to the production of hydrogen. The initial merits of different catalysts for industrial implementation have been analysed, and some of them have been subjected to semi-industrial tests to contrast against commercial comparators.

The project WP structure follows itself the bottom-up assembly route and multiscale study of the hybrids. Thus, the mains results for each WP, presented below, represent milestones in the progressive integration and characterisation of materials into more complex structures:

WP1 The strict quality and reproducibility requirements on the industrial nanocarbons led Thomas Swan Ltd. to use of Statistical Process Control (SPC) and Statistical Quality Control (SQC) techniques for further improvement in product quality of single wall carbon nanotubes (SWNT), multiwalled carbon nanotubes (MWNT) and graphene. These efforts have had a positive impact on the quality of their materials beyond the carbon family and improved their competitive positions as a manufacturer of high-quality nanomaterials.

For specific hybrids, the addition of small amounts of Thomas Swan’s CNTs (<2wt.%) led to substantial increases in photocatalytic activity e.g. (30% H2 production), confirming the view that their high-quality nanocarbons could find use as “additives” to improve existing photocatalyst.

WP2 A wide variety of functionalisation routes for MWCNTs and graphene to produce stable dispersions and later to control hybridisation and interfacial process were successfully developed. They use environmentally benign conditions as far as possible, and water as a solvent medium. The functionalisation methods developed included: cutting and oxidation of MWCNTs by acid treatment, diazo-coupling, and microwave-assisted. Their availability for widespread application in nanocarbon handling, dispersion and hybridisation is a key results that will have impact beyond the field of study of CARINHYPH. Preliminary work on implementing these strategies to supported or self-standing nanocarbon ensembles is considered highly innovative and with enormous potential for various applications.

WP3 The development of synthetic routes to produce nanocarbon/semiconducting metal oxide hybrids with different architecture (gyroid, mesoporous oriented, membrane, etc), interfacial chemistry and covering the whole range of volume fraction (0 – 100% nanocarbon) is a result of the project that we expect to impact the application of hybrids in other applications based on interfacial energy/charge transfer in inorganic/nanocarbon systems, such as sensors, pseudocapacitors, photovoltaics and piezoelectric energy harvesting.

WP4 Most of the hybrid materials developed in CARINHYPH have a complex structure, with relevant features across various length-scales, large surface areas and large interfaces. Thus, the characterisation of hybrids has required the use of a wide range of techniques (electron microscopy, XRD, SAXS-WAXS, FTIR, XPS, EELS, UPS, TGA, gas adsorption, UV-Vis, NMR, Raman). In addition to the conventional information expected for each technique, they have provided evidence of strong interaction between the nanocarbon and inorganic phases leading to the formation of electronic junctions. Additionally, the results of WP4 highlight the unusual structure of the metal oxide phases produced under non-oxidative atmospheres (so as to preserve the nanocarbon), with important implications for their transport properties.

WP5 A vast number of hybrid samples (based on WO3, TiO2, ZnO, SnO2, Ta2O5 and Nb2O5; CNT- and graphene-base) of different types were subjected to photocatalytic tests, mainly for H2 production under UV irradiation, but also including the degradation of organics. These experiments include studies the use of 3 different lab-scale reactors and the study of reaction parameters (concentration of catalyst, co-catalyst, sacrificial agent, irradiation power, etc). H2 activities as high as 2.2mmol/h with Pt co-catalyst and 1100 without, have been obtained in the project.

WP6 A key result of the project is the study of hybrids as semiconductor/nanocarbon electronic junctions through measurements of the junction electronic and optoelectronic properties. These electronic structure of hybrids has been determined by Kelvin probe, UPS and optical measurements. Mesoporous hybrids with in the micron range have been directly subjected to transport measurements. Advanced pump-probe spectroscopic technique have been also used to study these materials, in many cases for the first time, to relate transport properties to photocatalytic performance.

WP7 Selected electrospun photocatalysts were tested under semi-industrial conditions and compared with commercial catalysts. A key results of this WP was to provide further evidence that electrospun catalyst have higher photocatalytic activity than nanoparticles of the same composition, which we attribute to their mesoporous structure of interconnected nanocrystals. These results, combined with the observation that H2 evolution rates saturate at very low catalyst concentrations, have important implications for the design and further scale-up of electrospun catalyst.

WP8 An extensive toxicological survey of the starting materials and the final hybrids has been performed. These investigations allowed to get perspective on potential EHS impacts of these novel materials and eventual factors (i.e. psychochemical properties) affecting their toxicity. A LCA was established and the materials developed in CARINHYPH contrasted against established technologies for hydrogen production.

Potential Impact:

CARINHYPH is a research project located towards the fundamental science spectrum of technology development. Its activities started at a technology readiness (TRL) level of 1 (basic principles observed) - 2 (technology concept) and throughout the project progressed to TRL 2 to TRL 3 (experimental proof of concept). In this context, the impacts of the project can be grouped as: a) professional development of high-skilled citizens in key sectors for the development of the EU b) scientific and technological advances in KETs (nanotechnology, advanced materials) and c) development of innovative multidisciplinary concepts in the energy, transport and biochemistry sectors.

-Professional development of high-skilled citizens in key sectors for the competitiveness EU. CARINHYPH has contributed to the formation of ca. 12 PhD students that benefited from interactions with a multidisciplinary consortium of research groups. In addition to regular visits between research groups, there have been various secondments that led to the foundation of long-lasting collaborations between groups. Furthermore, the project has been particularly beneficial for the professional development of young research group leaders, providing key support for establishing their groups at the forefront of scientific development in their fields on an international level. Initially, at the start of the project Dr Marchesan acted as postdoctoral research associated. Towards the end of it she became a lecturer at the University of Trieste and leader of a large research group at the Department of Chemical and Pharmaceutical Sciences. Her work on biological applications of supramolecular chemistry of peptides and other nanoscopic building blocks is currently supported by a prestigious Scientific Independence of young Researchers Grant from the Italian Ministry of Education and Research. Professor Dominik Eder, initially at the University of Münster, was promoted to a more senior position at the Institute of Materials Chemistry at the University of Vienna. Dr. Cherevan, a PhD student at the start of CARINHYPH, is currently starting his own research group under Prof. Eder Group’s umbrella. Dr Vilatela has also benefited from CARINHYPH. The current work of his work on multifunctional nanocomposites has incorporated various ideas of the project, leading for example to the concept of energy management in structural composites, currently funded by the ERC in the form of a Starting Grant (see also exploitation of results below).

- The project has made big contribution to the bottom-up assembly of nanostructured building blocks into complex architectures with emerging optoelectronic properties. The science developed in the project will impact the fields of chemical functionalisation of nanocarbons, hybridisation of nanocarbons with semiconductors, multiscale characterisation of hybrids, interfacial charge/energy transfer in hybrids and in general in the development of strategies to exploit the properties of nanobuilding blocks on a macroscopic scale.

- The arsenal of materials and techniques developed in CARINHYPH are of great interest in emerging technological sectors based on controlled charge transfer or energy storage at nanostructured interfaces containing nanocarbons. Amongst these, we identify: the electrification of the transport sector and need for structural energy storage, innovative concepts in energy harvesting including flexible energy managing devices, and the exploitation of charge transfer in special-tailored biological systems for detection and signalling. We expect CARINHYPH to have made contributions to these fields.


The plan layout for CARINHYPH’s dissemination activities along the whole duration of the project, both to the public at large and among the project participants, was described in the public deliverable 10.2 (Dissemination plan and updates). This document was updated two times along the project and was prepared not only to promote the project outcomes, but also to stimulate linkages and cooperation efforts among related research and technological development initiatives. Taking into account the low Technology Readiness Level (TRL) of the project, main targets have been peers in research. However, attention has also been paid to outreach activities and interaction with companies. The whole list of dissemination actions performed along the CARINHYPH project can be found in section 4.2A of this report. They can be summarized as follows:

- A press release announcing the start of the CARINHYPH project was issued on March 2013, which was reflected in 11 different media (CORDIS wire, Energy News, SINC, Madri+d, Madrid Network and Iagua amongst others).
- A project website ( containing a public and a private area was created in February 2013 and has been regularly updated.
- The findings of the project have originated 4 journal papers (4 currently under preparation), one book, and 34 symposium/congress/trade fair/workshop presentations.
- Concerning outreach activities, members of IMDEA explained the work under the CARINHPH project as part of Madrid Science week (editions 2014 and 2015).
- A two-day project workshop entitled “First workshop on nanostructured materials for light harvesting technologies” was organized in November 2015 in collaboration with the Spanish solar fuels network. The UK Solar Fuels Network and the Spanish CO2 valorisation network also collaborated in the meeting. Around 50 people per day attended this event.


The strategy and the concrete actions the CARINHYPH consortium has follow for the protection and exploitation of the project results was described in deliverable 10.3 (Exploitation plan). This document was updated twice along the project (this whole report being considered as the second update) and was prepared in order to extract value of the project potential exploitable results. Full description of the potential exploitable results can be found in section 4.2B of this report (confidential) and can be summarized as follows.

- The expected short-term impact and primary objective of the CARINHYPH project has been the exploration of synthesis routes of novel inorganic/nanocarbon hybrids for energy generation by photocatalythic hydrogen production, understanding nucleation, templating and “heat sink” effects at nanoscale and implications for bulk device properties. The nature of this challenge has a very strong scientific component, which is in fact reflected in the consortium composition (6 out of the 8 partners belong to academia).

- Taking into account that the potential applications of nanocarbon-inorganic hybrids is quite broad and not limited to hydrogen production (solar energy conversion, water and air purification, self-cleaning surfaces, ...) the production of nanohybrids engineered for charge-transfer processes through interfacial tailoring is expected in the medium-term.

- Finally, in the long-term, the production of bulk quantities of high-efficiency photocatalythic nanohybrids by scalable routes starting from commercially available nanocarbons is foreseen.

The Exploitation Strategy Seminar service offered by the ESIC services and the Industrial Advisory Board of the project (composed of representatives from Repsol, the Fuel Cells & Hydrogen Joint Undertaking, IATP Ltd, Abengoa Research and Belenos Clean Power) have provided useful advice on the possible application range of the outcomes of the project. This has been complemented by the findings of deliverables 7.4 (roadmap for industrial deployment and potential impact of the technology), 8.4 (LCA report), and 8.5 (EHS report).

Further RTD activity in the field has been so far the most evident result of the CARINHYPH project. Relater to this, it’s worth mentioning that 2 key researchers of the project have obtain prestigious research grants to continue work on the subject. Therefore, the short-term sustainability of the CARINHYPH project is ensured. Those projects are the following (see also impact sub-section above):

- STEM (Structural energy harvesting composite materials): ERC starting grant, gran agreement number 705365, estimated starting date on may 2015, principal investigator Dr. Juan José Vilatela (IMDEA).

- HOTSPOT (HeterOchiral, shorT, Self-assembling Peptides fOr Therapy): SIR Grant (Scientific Independence of young Researchers), project ID RBSI14A7PL, start date on 2015, principal investigator: Dr. Silvia Marchesan (INSTM).

The management of intellectual property within the CARINHYPH project mainly follows the DESCA model Consortium Agreement. It has been negotiated and signed by all partners. In essence the agreement covers the following main points:

- Background: All partners relevant background/ pre-existing know-how that is required by each partner for the execution of their tasks within CARINHYPH will be made available free of charge for the execution of the project. Use of this background for exploitation will be available under terms defined in accordance with the GA.
- Foreground: no preferred rights to exploitation have yet been outlined by express decision of the consortium. Overall, there is consensus that exploitation strategies should follow the emergence of scientific results and then dealt with ad hoc, but that premature exploitation strategies that could interfere with research activities should be avoided in the interest of the consortium.
- All results will be considered as confidential unless specific authorization for disclosure is granted by the consortium.
- Access rights: Contractors have royalty-free, meaning at no cost, access rights to the foreground needed to carry out their work in the project and during its duration.

List of Websites:

For more information on this document or CARINHYPH, please contact:

Dr. Juan José Vilatela – CARINHYPH Technical Coordinator

Miguel Ángel Rodiel – CARINHYPH Project Manager

Germán Infante – CARINHYPH Exploitation and Dissemination Manager

Fundación IMDEA Materiales
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